In recent years, there has been a technique of changing reproduction modes of music content by software processes using a personal computer, this technique being referred to as DTM (Desk Top Music). Since these processes require the user to have knowledge about editing of music content using a personal computer, a technique of changing reproduction modes of music content according to simpler operations than those of the foregoing technique or unintentional body motions of the user has been proposed.
For example, Japanese Patent Application Laid-Open No. 2003-85888 describes a portable music reproducing device that detects a walking pitch and changes a music tempo according to the detected walking pitch.
In addition, Japanese Patent Application Laid-Open No. 2005-156641 describes a reproduction mode controlling device and so forth that detect, for example, a walking tempo of the user, and change the reproduction speed and so forth of music content that is being reproduced according to the detected walking tempo.
The devices described in the foregoing patent documents change the reproduction speed of music content according to the walking or running tempo of the user. However, the range of which the reproduction speed of one title of music content was able to be changed was limited and the devices did not always reproduce music content at user's desired tempo.
In addition, the method of simply selecting a song having a tempo nearly equal to the detected tempo from a plurality of songs had a problem of which the selected song was not always comfortable for the user. In other words, songs for which the user feels comfortable are, for example.
Firstly, when the tempo quickly increases from a stop state or a running state to a dashing state, it is preferred that songs be quickly selected according to the tempo that is increasing.
Secondly, when the tempo changes in the decreasing direction from a running state to a walking state or a stop state, it is preferred that songs be not quickly changed, but the running state be kept for a while and then it change to a walking state or a stop state.
Thirdly, when the change rate of a tempo is small, for example, in a walking state or a running state with a constant tempo, it is preferred that songs be not frequently changed.